<!DOCTYPE html>
<html class="reftest-wait">
<title>Reference for scroll timeline with a specified scroller</title>
<style>
  #scroller {
    overflow: scroll;
    width: 100px;
    height: 100px;
    scrollbar-width: none;
  }

  #contents {
    height: 200px;
  }

  #box {
    width: 100px;
    height: 100px;
    background-color: green;
    transform: translateX(50px);
  }
</style>

<div id="scroller">
  <div id="contents"></div>
  <div id="box"></div>
</div>

<script>
  window.addEventListener('load', function() {
    const scroller = document.getElementById("scroller");
    // Move the scroller to the halfway point.
    const maxScroll = scroller.scrollHeight - scroller.clientHeight;
    scroller.scrollTop = 0.5 * maxScroll;

    document.documentElement.classList.remove("reftest-wait");
  });
</script>
